I'm running a few ubuntu 18.04 servers in a Windows AD environment. The servers have no problem getting IPs via DHCP, but the DNS settings specified in option-6 are not written to any files.
Originally, I just updated /etc/resolv.conf, but this config wouldn't hold after a reboot. The standard 18.04 image uses NetPlan so we aren't concerned here about NetworkManager. After tracing it back to systemd-resolved and having to hardset the nameservers in the /etc/systemd/resolved.conf things seem to be working.
My question is simply how does one rectify dhcpcd option-6 with systemd-resolved? I don't want to have to hardset these variable on the creation of each server.
Also, dnsmasq doesn't seem to be an issue here, it's caching just fine as /etc/resolv.conf still points to 127.0.0.1 as long as /etc/systemd/resolved.conf has the DNS settings.